No hackle, just wrapped hook with some wool yarn and then a mix of brown and orange squirrel hair dubbing. Tied the elk hair at the bend with the tips going out for a tail, then brought that forward, tied the ends down behind the eye and trimmed the head.

Im not sure the appropriate size for this fly (maybe someone on the board has a better a recommendation), but I think 10 and 12 would work.

BTW, these were on size 6 but I was trying them for bass and/or bream, not trout.

I really like the use of the spikey squirrel dubbing its a wonderful body material. I used it several years ago for my nymph patterns, but have shifted my tying away from nymphs lately. I think many of us who have been focusing on delicate mayfly dries have subconsciously started reaching for the "convenient package" instead "of cutting off the skin" for most of our flies. Then we go back and rough up the synthetic.

I believe the Cooper Bug was originally tied to represent a caddis emerger (?)/ terrestrial/ attractor. The pattern goes back a long ways. For Smokies Trout, MY suggestion would be to tie it down what you have down to a size 14 or 12 2xl hook. I'd sub a more buoyant material for the wool and use a paste floatant to keep it in the film. I'm sure you will catch trout on them.
Randall Sale
the Kytroutbum

Squirrel is becoming one of my favorite tying materials. I use Haretron dubbing alot, but use squirrel tails for many fly tails and have been using it for hackle (pretty pleased with results). Any of the ends I clip off when making hackle, I save and mix in with Haretron, so much of my dubbing is now rabbit and squirrel mix.

I use Dave Whitlock's Red Fox Squirrel Nymph tyed as a Stonefly as my go to fly for rivers in Wyoming as they clear from the snowmelt. I use the body hair rather than the tail. The tail makes a nice mini streamer, size 14-10 if you touch the ends in super glue as you tie them in.

Slider-
I tie my RFSN's weighted three ways. 1)Weighed heavily, with two tungsten beads ,one under thorax, other at head, along with lead wire to get them down toward the end of snow melt. 2) Weighted by tungsten bead head only 3) then just lead wire. I use the lighter two in the Smokies.

I use rubber legs on my ties for larger Western rivers and wind saddle hackle legs for streams where the trout have a better view, due to slower flow and clarity, similar to Smokies.

I had surgery last winter so I did a lot more tying than testing this summer. I've played with converting some of Ray Bergman's wet fly patterns into small streamers. I found that the squirrel and calf tail need to be tied sparse and have some superglue on their bases as they are tied in. (They are "hard" and slippery if you don't).